Systematic Study of StripBlock Scintillators: Progress Report

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Systematic Study of Strip/Block Scintillators
Progress Report

• E.P. Jacosalem, S. Iba, N. Nakajima, H. Ono,
• A.L. Sanchez, A.M. Bacala H. Miyata
• ILCCAL TV Meeting
• June 13, 2005

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Outline

• Background of the study
• Research Design and Methodology
• Scintillators surface covering and length
  variation
• WLS fibers length variation
• Results
• Summary
• Future plans

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Background of the study

• RD for new calorimeters to achieve accurate
  measurements of the SM
• Accurate precise measurements require fine
  segmentation
• Fine segmentation can be acquired from small
  scintillators
• Motivated to come up with new calorimeter design

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Research Design Methodology
Setup

• Trigger Scintillator (about 1cmx8cmx5mm )
  directly connected to PMT
• Source 90Sr (beta-ray)
• PMT (sensor) 16 Ch MAPMT H6568-10, HV -950V
• PMT (trigger) H3164, HV -900V
• Sensor Strip type scintillator ( length
  4,8,12, 16cm)
• Block type scintillator (thickness 2,
  4, 5, 6 and 8mm)
• WLS fiber diameter 1.0mm 1.6mm (length 20,
  40, 60, 80, 100, 120, 180, 300 cm)

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Scintillators surface covering and length
variation
Research Design Methodology cont..
3M Reflective Mirror
Teflon
10x60x2mm
Black Sheet
White Paint with Teflon
White Paint Surface Covering (1.7mm groove for
1.6mm WLS fiber)
Gold Coat

• Compare each type using
• ADC system
• Use WLS fiber with diameter of 1.0mm and 1.6mm
• Determine the systematic error

White Paint
Aluminum Evaporation
10x40x2mm scintillator (1.1mm groove)
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Results

• 3M reflective mirror has the greatest light
  yield
• PH increasing with scintillator length on 3M
  reflective mirror, teflon, white paint with
  teflon and aluminum evaporation.
• PH is almost constant with scint length on white
  paint and black sheet surface coverings.
• No comparison for gold coat since cannot do gold
  coating for strips longer than 40mm.

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Results cont..

• 3M reflective mirror has the highest pulse height
  
• PH slightly increases with sensors length on 3M
  reflective mirror, teflon, and white paint with
  teflon
• PH on white paint, aluminum evaporation and black
  tape are almost constant.

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Results cont

• Sensors type
• 3M reflective mirror covered 10x40x2mm scint.
• varying WLS fiber length
• plotted the ln of ADC count to achieve the
  attenuation length
• Attenuation Length
• 1.6mm dia 2.01m
• 1.0mm dia 1.19m

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Summary

• 3M reflective mirror covered scintillator found
  to have the greatest pulse height.
• Scintillators using 1.6mm WLS fiber had greater
  PH compared to scintillators with 1.0mm fiber
• PH increasing with scintillator length on 3M
  reflective mirror, teflon, white paint with
  teflon and aluminum evaporation.
• PH is almost constant with sensors length on
  white paint and black sheet surface coverings.
• Attenuation Length
• 1.6mm dia 2.01m
• 1.0mm dia 1.19m

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Future plans

• Do ADC measurements for block-type scintillators
  (thickness varied).
• Do ADC measurement for position dependence for
  strip type scintillator.
• Do simulation for light transmission for strip
  type.